SAN FRANCISCO — We received a lesson Saturday aboutwhat can happen in 2013 when the Giants’ pitching is not, like, you know, totally awesome.

They walk off the field a 6-3 loser to the St. Louis Cardinals at AT&T Park. That happens.

Ryan Vogelsong struggles a bit and gives up five runs and the team’s batters seem to have no prayer of scoring six runs to pick up Vogelsong and still post a victory. That happens.

And it raises eyebrows that the Giants’ offense in 2013 could be following the same — or worse — path of frustration taken by last season’s offense, which scored the 12th-fewest runs in baseball and turned so many games into needless meat grinders. That happens.

One quote especially stood out in the eyebrow-raising category.

“You want me to tell the truth, I feel a little lost,” said Pablo Sandoval about his plate appearances.

Keep in mind that Sandoval was the Giants’ most productive hitter of the day, driving in two of their three runs and smacking a homer over the left field wall. Sandoval was nevertheless perturbed that he swung through a couple of fastballs from St. Louis’ rookie starter, Shelby Miller.

“When I miss a fastball down the middle the way I did, I know I’m lost,” Sandoval said. “When I feel good, I don’t miss those pitches.”

If Sandoval is lost, then how do you describe the mysterious locality of Marco Scutaro, who is batting .105 after five games? Or of Brandon Belt, who is hitless in all three games he’s played? As of Saturday evening, the Giants had the sixth worst team batting average in the majors (. 210) and had scored the fourth fewest runs per game (2.4).

Giants manager Bruce Bochy professed not to be concerned. The season is a week old. There are 25 weeks to go.

“It’s a small sample size,” Bochy said. “It’s early. Guys are just getting into the rhythm of the season. We’ll get it going. Look at Belt today. He smoked two balls and they were just both caught.”

“That’s the way the game is sometimes,” affirmed catcher Buster Posey.

All correct. But the result was this: Over 17 innings Friday and Saturday, in the Giants’ first two home games this season, they drove in just one runner with an actual hit — a Sandoval single on Saturday. In Friday’s 1-0 victory over St. Louis, the Giants’ only run was “driven in” by a bases-loaded walk. Saturday, two of their three runs came on homers by Hunter Pence and Sandoval.

Right now, the Giants’ stellar pitching performances (and the ensuing 3-2 record) has mostly served to obscure the offensive ulcers. As we all know, the Giants’ fan base loves to obsess and worry. Unfortunately, many of those worries are about meaningless folderol, such as whether former Giants closer Brian Wilson will show up for Sunday’s championship ring ceremony, or why Barry Bonds has declined to participate in this weekend’s celebrations.

Uh, if Wilson didn’t respond to the Giants’ invitation, that’s his prerogative. If Bonds was not big on team bonding as a player, why expect him to be that way as an ex-player? Who cares? The true worry of any Giants follower in 2013 should be about the team’s inability to hit on a timely basis — or to hit at all.

Obviously, a team can display mediocre-to-average batting accomplishments and still become a World Series champion. The Giants did that in 2012. But you can’t guarantee such a formula will repeat. The plan for this season was to retain the superior arms while nudging the offense up a notch and giving the pitching more of a cushion.

The presence of Scutaro and Pence in the lineup for a full season was supposed to do some of that nudging. The maturity of Belt into a more intimidating batter was also supposed to help nudge.

There has been minimal nudging to date, even if Pence’s homer Saturday was a positive sign.

Often, when a team has trouble scoring, you point your finger at the cleanup batter. Which, in this case, would be Posey. But on Saturday, Posey only came up once with a runner on base. He grounded into a fielder’s choice. And when Posey doubled in the eighth inning with no outs, the next three Giants batters — Pence, Belt and pinch-hitter Hector Sanchez — all made outs.